If a person is lost in the wilderness, they have two options.
For scientists interested in the question of whether intelligent aliens exist, the options are much the same.
Most scientists are confident that life exists on many of the300 million potentially habitable worldsin the Milky Way galaxy.
Astronomers also think there is adecent chance some life forms have developed intelligence and technology.
But no signals from another civilization have ever been detected, a mystery that is called The Great Silence.
Im aprofessor of astronomywho has written extensively about the search for life in the universe.
I also serve on the advisory council for a nonprofit research organization thatsdesigning messages to send to extraterrestrial civilizations.
It’s free, every week, in your inbox.
These efforts are like building a big bonfire in the woods and hoping someone finds you.
But some people question whether it is wise to do this at all.
The Pioneer 10 spacecraft carries this plaque, which describes some basic information about humans and the Earth.
In 1977, NASA followed this up with the famousGolden Recordattached to theVoyager 1 spacecraft.
These spacecraft as well as their twins, Pioneer 11 and Voyager 2 have now allleft the solar system.
Electromagnetic radiation is a much more effective beacon.
Astronomers beamed the first radio message designed for alien ears from theArecibo Observatoryin Puerto Rico in 1974.
Since M13 is 25,000 light-years away, you shouldnt hold your breath for a reply.
This ever-expanding bubble of earthly babble has already reached millions of stars.
One is using a giant new radio telescope, and the other is choosing a compelling new target.
These on-off pulses are like the 1s and 0s of digital information.
The other attempt is targeting only a single star, but with the potential for a much quicker reply.
The first is:Who speaks for Earth?
But there is also a much deeper question.
If you are lost in the woods, getting found is obviously a good thing.
Before he died, iconic physicistStephen Hawking was outspoken about the dangerof contacting aliens with superior technology.
And there is interest.
To date, no international regulations govern METI, so the experiments will continue, despite concerns.
For now, intelligent aliens remain in the realm of science fiction.
It doesnt end well for humanity in the books.
If humans ever do make contact in real life, I hope the aliens come in peace.
